Pulp & Paper Processing

We provide a wide range of products and services to the pulp and paper processing industries.

DREW™ Pulping Aid
DREW KPA 300 pulping aid is a patented chemistry for improving the efficiency of the pulping process by improving mass transfer of pulping chemicals and by-products during the cook. It has been shown to improve pulp yield by 1 to 2.5 points while at the same time reducing cooking liquor requirements, reducing recovery loading, reducing rejects and improving pulp washing. It allows mills to produce maximum pulp while minimizing raw material and energy input. It is effective at all levels of sulfidity, and it has been successfully applied in conjunction with anthraquinone, but is usually applied without it.

DREW KPA 300 pulping aid is successfully applied in a broad range of pulping processes, including:

Kraft and soda/AQ
Brown and bleached
Hardwood and softwood
Batch, conventional continuous, Kamyr® MCC, Kamyr Lo-Solids

Through the application of DREW KPA 300 pulping aid mills have achieved significant reductions in alkali charges, significant reductions in recovery loading, increased production rates, increased yields, improved washing and reduced Kappa numbers.

Kamyr® is a registered trademark of Andritz, Inc.

DREWFAX® Scale Control Agents
When scale causes productivity or quality problems that have a significant economic impact on a mill, we are the market leader, with the analytical capabilities to properly diagnose the problem and the experience to recommend the right solutions. Some scale problems can be solved by making process changes. In other cases, scale can be eliminated by DREWFAX scale control agents, formulated specifically for the special needs of pulp and paper mills.

We have successfully eliminated scale problems in many parts of the pulp and papermaking process, including:

Kraft Digesters
The productivity of many continuous kraft digesters is hindered by the growth of scale in heaters and screens. As these digesters are pushed to higher production rates, increased heat and shear increase the potential for scale. DREWFAX® 342 deposit control agent is the leading technology for kraft digester antiscalants and represents a significant advancement in kraft digester antiscalant technology.

Through the application of DREWFAX 342 deposit control agent scale buildup throughout the digester can be reduced or eliminated, resulting in the following advantages:

Increased operating time between digester shutdowns for scale removal
Improved liquor circulation (and pulp uniformity)
Less frequent heater cleanings
Reduced digester corrosion (due to acid cleaning)

The results achieved with DREWFAX 342 deposit control agent are unequaled. Heater life has typically doubled or tripled. In one case, where the product was applied to a previously untreated digester, heater life increased five fold. The product has also shown superior ability to reduce scaling in other areas, such as the cooking screens, in-line drainers, and top separator. It is also suitable for application to batch digesters with indirect heating for the control of scale on heat-transfer surfaces.

The following reference materials are available upon request

Black Liquor Evaporators
Green and White Liquor Lines
De-inking Plants
Bleach Plants

ECOPULP¹ Enzymes
We have teamed up with AB Enzymes to provide bleach-boosting products to the North American market. AB Enzymes is one of the world's oldest and best-known enzyme producers and the first company to evaluate enzymes in pulping processes. AB Enzymes holds the patent for bleach boosting enzymes in oxygen delignification systems. We are a recognized leader with our DREWFAX® digester and bleach plant antiscalant programs. Combining the two, we can now use our pulp mill knowledge to provide bleaching chemical cost reductions.

ECOPULP enzymes provide numerous advantages at minimal cost:

Reduced chemical costs: ECOPULP enzymes dramatically reduce the consumption of bleaching chemicals. Total chlorine dioxide consumption has been reduced by 15-20 percent.
Increased pulp production capacity: ECOPULP enzymes allow pulp production capacity to be increased in mills where where pulp bleaching sequences are designed for producing elemental chlorine-free pulp.
Higher pulp brightness: ECOPULP enzymes make it possible to produce pulp with higher final brightness, while reducing chemical charges. In totally chlorine-free bleaching, the product allows high final brightness without compromising the viscosity and strength properties of the pulp.
Efficacy under widely differing process condition: The ECOPULP enzyme product range is optimized for conditions that may vary in the pH range from 4.5 to 8.5 and temperature range from 110° F to 195° F. These products are particularly suitable for addressing the current trend toward water system closure, which results in higher process temperatures.

¹ AB Enzymes GmbH.

DREW™ Dechlorinating Agents
Many pulp mills use caustic soda and/or a reducing agent to remove chlorine and chlorine dioxide residues from bleached pulp prior to high-density storage or to improve the efficiency of bleach plant chlorine and chlorine dioxide scrubbers. Sodium hydroxide, white liquor and/or sulfur dioxide gas are commonly used for these applications.

Sulfur dioxide gas can be cost-effective, but adds potential safety and corrosion hazards. Sodium hydroxide and white liquor need to be applied at high rates to be effective, which results in significant costs to the mill. Additionally, the high alkalinity of these chemicals can cause calcium carbonate scale in scrubbers, which reduces their efficiency.

DREW™ 6140 dechlorinating agent is an aqueous solution of sulfur-based reducing agents, which effectively destroy chlorine and chlorine dioxide in air, water and pulp streams at a significantly lower cost than caustic soda or white liquor. It is safe and easy to handle and can be applied directly to the bleached pulp or to the scrubber recirculation line. It has a pH near neutral and will not cause scrubber scaling.

The following reference materials are available upon request.

DREWSPERSE® Pitch and Stickies Control
AMERSTAT® and BIOSPERSE® Microbiocides
GENEROX™ Generator for Small Scale Generation of Chlorine Dioxide
DREWPLUS® Foam Control Agents
Retention and Drainage Aids
DREWCLEAN® Felt and Equipment Cleaners
Clarification and Sludge Dewatering Enhancement
Corrosion Inhibition

For more information, please contact your local sales representative.